STEP 7 Code To Interface Multiplexed BCD Displays

[TodHead]

Hi All,

Desperately looking for STEP 7 code example to help urgent project!

I am wishing to interface 5 (five) multiplexed 6 digit BCD displays. As a guide I have the original STEP 5 code - unfortunately I am not familiar with STEP 5 at all (and am new to STEP 7!) but can glean the main principle of the method.

The first output word that is output to the display(s) is constructed as follows:

Hi order byte:
bits 0-3: BCD bits 1,2,4,8
bits 4-7: Display Digit Select 1 to 4

Lo order byte:
bits 0-1: Display Digit Select 5 to 6
bits 2-6: Display No.1 to Display No.5 Select
bit 7: Flash 1

The relevant bits of the second output word that is output to the display(s) are:

bit 1: Flash 2
bit 2: Flash 3
bit 3: Flash 4
bit 4: Flash 5

I have an STL routine for non multiplexed displays that I can deconstruct as a starting point but I would rather have a LAD/FBD template as a starting point.

Surely someone has done this before and can give some guidance to this classic exercise?!?

 

[TurpoUrpo]

Post the s5 code. Atleast I did not understand your description.

 

[L D[AR2P#0.0]]

Example attached.

I put decimal data in the temp area for testing purposes. You will need to copy the data you wish to display into this area instead of my test data. Similarly I have created the multiplexed bits in the stat area of the FB, you will need to assign these to your actual output bits. I tested this in plcsim using single scan mode and monitored the instance DB to check the correct bits came on.

 

[TodHead]

Thanks for your help L D[AR2,P0.0] I will have a look at this when I go on shift tonight. We have been given a solution in SCL which may work...